A speed/torque enhancing power transmission is disclosed that translates slow rotating, high torque motion to high rotation, low torque motion or alternatively high rotating low torque motion to low rotating high torque motion and is suitable as a speed increaser for use in a device like a wind turbine. As a speed increaser the transmission has certain advantages, such as reduced weight and/or size compared to other units having the same performance characteristics. The speed increaser employs a pair of externally toothed spur gears orbiting in a non-rotating manner 180° out of phase inside an internally toothed ring gear. The input drives the ring gear and the orbiting spur gears drive separate eccentrics on the output shaft extending in opposite directions to provide dual output. In one embodiment, cross guide projections on the spur gear and cross guide projections on the housing engage slots in a swash plate.